Broken Hill's new mineral sands processing plant is now in the commissioning phase before full production starts in about three weeks.

The commissioning phase involves checking that every component of the plant works efficiently and safely.

The plant at Cristal Mining's Pinnacles Road site is expected to triple the production of the current facility.

This will allow the company to process the one-million-tonne stockpile of mineral sands that is current stored at the company's Gingko mine near Pooncarie

Cristal's manager of mineral processing, Clayton Trengove, says some construction work is still going during the day while commissioning happens at night.

"We couldn't be happier with the way the plant is actually reacting on material - it's ticking through," he said.

"We've actually sent a couple of trainloads through to the port of Adelaide for sale, so we've got some saleable material that's already been through.

"Looking forward to the next few weeks where we can finish it off altogether and demobilise our construction site and make it into operations."

Mr Trengove says the new plant is working better even than the existing plant that it sits alongside.

"The fluid-bed dryer is probably working better than our current leucoxene plant, and also the quality that the new BHT plant is putting out is actually of better quality than our current leucoxene circuit as well," he said.

Cristal Mining will employ about 650 people in Pooncarie and Broken Hill once production is in full swing, and up to 1,000 once its Campaspe mine is open between Balranald and Ivanhoe late next year.

"We had to upgrade our maintenance team so we've put on a couple of extra electricians and mechanics," Mr Trengove said.

"We've also put on four new operators, and we're probably looking for another two or three.

"The mines down there had to put on extra people for the Snapper and Gingko upgrades, and also the extra truck drivers who are needed to haul the material in.

"We're starting an extra train, so obviously that's a whole new train crew - it's created a fair few numbers employment-wise."